Power distribution system

ABSTRACT

A power distribution system includes a plurality of power distribution modules connected to at least one power supply and configured to receive power therefrom. A power distribution bus connects the power distribution modules of the plurality of power distribution modules in parallel. The plurality of power distribution modules executes a distributed system policy management protocol over the power distribution bus to control a supply of available power from the at least one power supply to loads connected to USB charging ports of the power distribution modules.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a National Stage application of International PatentApplication No. PCT/EP2017/068491, filed on Dec. 27, 2017, and claimspriority to Provisional Application Ser. No. 62/440,508, filed Dec. 30,2016, which are hereby incorporated by reference in their entirety.

TECHNICAL FIELD

This application relates to a USB Power Distribution System havingdistributed system policy management.

BACKGROUND

In a Power Distribution System having USB Type-C outlets, the power issupplied and controlled per the Power Delivery specification (PD Spec).The PD Spec is implemented as a software stack (PD Stack). The PD Specis published by the USB Implementers Forum, Inc. (USB-IF), and isavailable as part of the USB Specification download package, such as USBSpecification download packages revs 3.0 through 3.2 or the like, whichinclude the USB PD Spec, Engineering Chang Notices, and thecorresponding Adopters Agreement. In a USB device which functions as aPower Provider, the source port is implemented as a defined software andhardware design comprising a Physical Layer, Protocol Layer, PolicyLayer, and Device Policy Manager Layer.

Optionally, as the uppermost layer of the PD protocol stack, a SystemPolicy Manager (SPM) Layer may be implemented, usually as part of theOperating System on the device providing the Power, for example aDesktop PC, Automobile Dashboard mounted Infotainment System, or an ACPowered Desktop Monitor. The SPM is integrated into the device thatcontains the Primary power Converter (usually, an AC Line Powered PowerSupply). The primary function of the SPM is to ensure that the totalpower supplied to the downstream ports is within the capability of theprimary power converter.

In order to regulate the supply of the available power in a logical andsafe manner, known systems only permit one SPM and only one Primarypower Converter to be active on the USB bus at one time. In these knownsystems, it is not permitted to connect together two or more powered USBtype-C ports and have them share the task of System Policy Management.

SUMMARY

According to the present disclosure, a power distribution systemincludes a plurality of power distribution modules connected to at leastone power supply and configured to receive power therefrom. A powerdistribution bus connects the power distribution modules of theplurality of power distribution modules in parallel. The plurality ofpower distribution modules executes a distributed system policymanagement protocol over the power distribution bus to control a supplyof available power from the at least one power supply to loads connectedto USB charging ports of the power distribution modules.

Each power distribution module of the plurality may additionallycomprise memory storing a power system database identifying each powerdistribution module of the plurality of power distribution modules and atotal power required by each power distribution module. The power systemdatabase may additionally store a total power available from the atleast one power supply. The power system database may be updated eachtime a device is connected to or disconnected from the at least one USBcharging port and/or each time a power distribution module of theplurality is powered on.

A power distribution module according to the present disclosure maycomprise a power input configured to receive power from a power supply,at least one USB charging port, a microcontroller configured to controlthe distribution of power from the power input to the at least one USBcharging port, and a bus interface connectable to a power distributionbus. The bus interface may allow the microcontroller to send and receivesignals over the power distribution bus and the microcontroller may beconfigured to control the distribution of power from the power input tothe at least one USB charging port based on information received overthe power distribution bus.

According to the present disclosure, a method for distributing powerfrom at least one power supply through a plurality of power distributionmodules in communication over a power distribution bus comprisesmaintaining, in memory at each power distribution module, a power systemdatabase identifying each power distribution module of the plurality ofpower distribution modules and a total power required by each powerdistribution module of the plurality of power distribution modules. Themethod further comprises controlling, by a microprocessor of each powerdistribution module, a supply of power from the at least one powersupply to devices connected to USB charging ports of the powerdistribution module based on the power system database.

These and other objects, features and advantages of the presentdisclosure will become apparent in light of the detailed description ofembodiments thereof, as illustrated in the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is schematic diagram of a power distribution system according tothe present disclosure;

FIG. 2 is a schematic diagram of a power distribution module of thepower distribution system of FIG. 1;

FIG. 3 is a flow diagram of an embodiment for distributing power withthe system of FIG. 1;

FIG. 4 is a schematic diagram of the power distribution system of FIG. 1when installed;

FIG. 5 is schematic diagram of a power distribution system comprising acentralized system policy management controller; and

FIG. 6 is schematic diagram of another embodiment of a powerdistribution system comprising a centralized system policy managementcontroller.

DETAILED DESCRIPTION

Before the various embodiments are described in further detail, it is tobe understood that the invention is not limited to the particularembodiments described. It will be understood by one of ordinary skill inthe art that the systems described herein may be adapted and modified asis appropriate for the application being addressed and that the systemsdescribed herein may be employed in other suitable applications, andthat such other additions and modifications will not depart from thescope thereof.

In the drawings, like reference numerals refer to like features of thesystems of the present application. Accordingly, although certaindescriptions may refer only to certain figures and reference numerals,it should be understood that such descriptions might be equallyapplicable to like reference numerals in other figures.

Referring to FIG. 1, in the present disclosure, a USB Power Distributionsystem 10 is described that includes a Distributed System PolicyManagement Protocol controlling the supply of available power. The USBPower Distribution system 10 includes one or multiple Power DistributionModules (PD Modules) 12, which draw power from a single primary powerconverter (Power Supply) 14 or multiple parallel-connected primary powerconverters (Power Supplies) 14 over a power line 16. Although a singleline has been used to schematically represent the power line 16 forsimplicity, it should be understood that the power line may also includea common grounding wire for the PD Modules 12. The system 10 alsoincludes a PDM bus 18, to which each PD Module 12 is connected tofacilitate the Distributed System Policy Management Protocol thatcontrols the supply of the available power to the loads connected to thePD Modules 12 as described below.

Referring to FIG. 2, each PD Module 12 includes an embeddedmicrocontroller 20, one or more USB power outlets 22, which may be, forexample, USB Type-A outlets, USB Type-C outlets, or the like, and apower input 24 that is connected to the power supply 14 shown in FIG. 1,over power line 16. The microcontroller 20 communicates with the loadsattached to the USB power outlets 22 over communication lines 26 andruns an implementation of the USB PD protocol as defined by USB-IF forcontrolling power distribution to the USB power outlets 22 through oneor more voltage converters 27, switches 28 and/or the like.

As an additional function of the firmware, the PD Module 12 includes aPDM bus interface 30 connecting the PD Module 12 to the PDM Bus 18,shown in FIG. 1. The PDM Bus 18, shown in FIG. 1, is a sharedcommunication bus that connects all of the PD Modules 12 together. Forexample, the PDM Bus 18, shown in FIG. 1, may be formed as a single wireconnecting all of the PD Modules 12 in parallel.

The PDM Bus 18 may be implemented as an asynchronous peer-to-peer serialbus with normally-high, active-low signaling. Each PD Module 12 has aphysical driver circuit which may be implemented as an open-collector(pull down to ground) transmitter, and a voltage threshold sensingcomparator for receiving and monitoring the voltage on the PDM Bus 18.The physical driver circuit may be designed to withstand accidentalmiswiring, and may be connected without damage due to reversed DCpolarity, short circuit to the positive Power Supply, to Ground or tothe negative Power Supply.

Each PD Module 12 has a unique serial number or address, for example,implemented as a 4-byte binary value. Referring to FIG. 3, on power-upand at timed intervals afterwards, such as any time a device isconnected to, or disconnected from, one of the USB power outlets 22, thePD Module 12 broadcasts a message to discover if other PD Modules 12 arepresent at step 32. If other PD Modules 12 are found, a collision proofincrementing search protocol identifies the addresses that are occupied.At step 34, each occupied address on the PDM bus 18 is allocated anindex into a Power System Overview Database. Each entry in the PowerSystem Overview Database identifies each PD Module 12 by its uniqueserial number and also provides the total power required by said PDModule 12. The Power System Overview Database is maintained in memory36, shown in FIG. 2, at each PD Module 12. The Power System OverviewDatabase is shared so that a copy of the database exists in each of thePDM Modules 12 on the PDM bus 18.

The distributed database also has an entry for the total power availableto the system (power input) from the Power Supply or Supplies 14. Thepower input available may be configured, for example, by plugging acomputer into one of the USB downstream ports 22 and running a softwareutility to configure the Power Availability setting. Typically, thiswould be done at test when the system is packaged for sale. As sold, thesystem 10 would typically consist of the Power Supply 14 and a number ofPD Modules 12, packaged and sold together. However, additional PDModules 12 may be sold separately and connected to the system 10.

Knowing the total power available to the system and the total power loadof all of the PD Modules 12, the microcontroller 20 of each of the PDModules 12 is able to control the load supported at the power sourcingUSB power outlets 22 on its individual PD Module 12 at step 36, incoordination with the microcontrollers 20 of the other PD Modules 12, sothat the total system power load does not exceed the capability of theavailable system power sources.

As illustrated by steps 38 and 40, any time a new load is presented, oran existing load is removed, at one of the PD Modules 12 (i.e. anywhereon the system), the shared database is updated so that each PD Module 12has information available to calculate the total load presented andpower output of the system so that it may continue to allocate power toits power sourcing USB outlets 22 without the total system power loadexceeding the available system power.

Thus, in effect, each PD Module 12 acts as a SPM controlling powerdistribution to its USB outlets 22. However, instead of merelydistributing the total power from a single power supply, the PD Modules12 communicate with each other over the PDM Bus 18 so that each PDModule 12 knows how much of the total available power is available toit. Each PD Module 12 is then able to act as a SPM and distribute powerto its USB power outlets 22 without exceeding the total available powerto the system.

Referring back to FIG. 2, the PD Modules 12 may also include one or morestatus indicators 41, such as lights (e.g. light emitting diodes(LEDs)), screens or the like, for providing a feedback to a user of thePD module 12. For example, the status indicators 41 may indicate thevoltage being supplied to a device connected to one of the USB poweroutlets 22, the available power in Watts or any other similarinformation.

Referring to FIG. 4, the USB Power Distribution system 10 isschematically illustrated as being installed on the underside of aconference room table 42. As seen, the PD Modules 12 may advantageouslybe spread around the periphery of the table 42 to provide a plurality ofdevice charging locations all connected to a single Power Supply 14 viapower line 16 under the table 42. The PD Modules 12 are connected to oneanother via the PDM Bus 18 to control the distribution of power from thePower Supply 14 in the manner discussed above. Although the power line16 and PDM Bus 18 are shown as being routed separately, in practice, thepower line 16, ground wire, and PDM Bus 18 may be three separate,parallel wires that are connected and routed together on the undersideof the table 42. Although FIG. 4 illustrates a table 42, the USB PowerDistribution system 10 may be mounted to any other structure inaccordance with the principles of the present disclosure where multipleUSB power ports are needed in close proximity to one another includingwithout limitation to desks, a bar, a countertop, or a community tablein a lobby, coffee shop, waiting room, library, airport lounge or gatearea or any other similar location.

Although the USB Power Distribution system 10 has been illustrated as asingular system in FIG. 4 for simplicity, it should be readilyunderstood that the system may be implemented in combination withwireless charging systems such as those described in U.S. PatentApplication Publication No. 2016/0181859, entitled ECOSYSTEM FORSURFACE-BASED WIRELESS CHARGING SYSTEM, which is hereby incorporatedherein by reference in its entirety.

Additionally, while the PDM Bus 18 may be formed as a single wire asdiscussed above, it should be readily understood that the PDM Bus 18 mayinstead be implemented through other known wired or wirelesscommunication links, such as Ethernet, Bluetooth, Wi-Fi or the like.

Although the system 10 has been described above as using generic PowerSupplies 14, the Power Supply 14 may optionally include a PDM Businterface 30, similar to that included in each PD Module 12, thatconnects the Power Supply 14 to the PDM Bus 18. The Power Supply 14 maythen automatically communicate (over the PDM Bus 18) the powercapability of the attached Power Supply 14 to the PD Modules 12 attachedto the Power Supply 14.

A PDM Bus interface 30 may also optionally be included in an upstreamCommunications Module to provide an interface between the PDM Bus 18 andthe larger world, such as via an internet connection, using either awired connection (for example, Ethernet or the like) or a wirelessconnection (for example, LoRa-WAN, SigFox, NB-IOT, Bluetooth, Wi-Fi orthe like). The Communications Module would maintain a copy of the PowerSystem Overview Database for the purpose of sending reports to alert theowner or user of the system 10 of events such as excessive load or afault in the system, or to make the system shut down or start up atspecified times, or for billing of the power delivered, or for controlof availability of the system.

A PDM Bus interface 30 could also optionally be included in a moduleintegrated into a building security or supervisory system connected tomotion detectors, security cameras and other security or controldevices, thereby allowing the system to automatically turn on and/or offor the like.

The USB Power Distribution system 10 advantageously provides moreflexibility that the currently implemented System Policy Managers, inthat, the number of PD Modules 12, and the number or capability of thePrimary Power Converter(s) 14 may be unknown at time of initial systeminstallation. If more power outlets are required, additional PD Modules12 can be added. If more power capability is required, the Primary PowerConverter can be changed for a higher power rated converter, oradditional power converter(s) may be added, with simple parallel wiringconnections. The Distributed System Policy Management of the USB PowerDistribution system 10 of the present disclosure advantageouslyautomatically compensates for these changes allowing the USB PowerDistribution system 10 to continue distributing power without exceedingthe total available power.

This is because there is no single device providing the System PolicyManagement; rather, the SPM function is shared and distributed equallybetween the multiple microcontrollers 20 running on each of the PDModules 12 in a cooperative manner according to a pre-defined PDM Businterface communication protocol separate from the USB communication busprotocol, and Power Distribution Bus protocol, defined by usb.org.

Additionally, if the total requested load at the PD Modules 12 exceedsthe total available power at the Primary Power Converter(s) 14, thedistributed System Policy Management of the USB Power Distributionsystem 10 may advantageously be programmed to implement different powercontrol strategies for different applications. For instance, the system10 may be configured to charge lower load devices first (e.g. to chargephones before laptops). Alternatively, the system 10 may be configuredto iteratively charge some devices at the full power requested whileinitially denying other devices any power, and then switching thosedevices that are receiving power at some time interval, therebyminimizing the total time to charge the collection of devices to acertain power level (e.g. 80% power) since many batteries charge moreslowly as they near full capacity. It should be understood that variousother control strategies and/or algorithms, including those thataccommodate Programmable Power Supply characteristics for fast charging,may be implemented by the system 10 depending upon the intendedapplication without departing from the scope of the present disclosure.

Although the System Policy Management of the system 10 has beendescribed as being distributed amongst the PD Modules 12, referring toFIGS. 5 and 6, wherein like numerals represent like elements, USB PowerDistribution system 110 may instead include a single centralized SPMmicrocontroller 144 linking PD Modules 112 to Primary Power Converter(s)114 and controlling power distribution from the Primary PowerConverter(s) 114 to the PD Modules 12. The centralized SPMmicrocontroller 144 may, therefore, control power distribution to all ofthe PD Modules 112 as outlined above and in a manner similar to the waya laptop processor distributes power to its USB ports, without exceedingthe total available power to the system 110. Additionally, by linking tothe Primary Power Converter(s) 114 and the PD Modules 112, thecentralized microprocessor 144 still advantageously provides the abilityto handle modularly incrementable power supplies 114 and PD Modules 112as they are added or removed from the system 110.

While the principles of the present disclosure have been describedherein, it is to be understood by those skilled in the art that thisdescription is made only by way of example and not as a limitation as tothe scope of the disclosure. Other embodiments are contemplated withinthe scope of the present disclosure in addition to the exemplaryembodiments shown and described herein. Modifications and substitutionsby one of ordinary skill in the art are considered to be within thescope of the present disclosure.

What is claimed is:
 1. A power distribution system comprising: at leastone power supply; a plurality of power distribution modules connected tothe at least one power supply and configured to receive power therefrom,each power distribution module of the plurality of power distributionmodules including a microcontroller and at least one USB charging port;and a power distribution bus connected to each power distribution moduleof the plurality of power distribution modules; wherein the plurality ofpower distribution modules is configured to execute a distributed systempolicy management protocol over the power distribution bus to control asupply of available power from the at least one power supply to loadsconnected to USB charging ports of the power distribution modules. 2.The power distribution system according to claim 1, wherein the powerdistribution bus is a single wire connecting the power distributionmodules of the plurality of power distribution modules in parallel. 3.The power distribution system according to claim 1, wherein each powerdistribution module additionally comprises a bus interface operativelyconnecting the microcontroller to the power distribution bus, the businterface allowing the microcontroller to send and receive signals overthe power distribution bus.
 4. The power distribution system accordingto claim 3, wherein the bus interface comprises an open-collectortransmitter for transmitting signals over the power distribution bus. 5.The power distribution system according to claim 3, wherein the businterface comprises a voltage sensing comparator configured to receiveand monitor voltage on the power distribution bus.
 6. The powerdistribution system according to claim 1, wherein each powerdistribution module additionally comprises memory storing a power systemdatabase identifying each power distribution module of the plurality ofpower distribution modules and a total power required by each powerdistribution module of the plurality of power distribution modules. 7.The power distribution system according to claim 6, wherein themicrocontroller is configured to transmit a signal over the powerdistribution bus to update the power system database each time a deviceis connected to or disconnected from the at least one USB charging port.8. A power distribution module comprising: a power input configured toreceive power from a power supply; at least one USB charging port; amicrocontroller configured to control the distribution of power from thepower input to the at least one USB charging port; and a bus interfaceconnectable to a power distribution bus, the bus interface allowing themicrocontroller to send and receive signals over the power distributionbus; wherein the microcontroller is configured to control thedistribution of power from the power input to the at least one USBcharging port based on information received over the power distributionbus.
 9. The power distribution module according to claim 8, wherein thebus interface comprises an open-collector transmitter for transmittingsignals over the power distribution bus.
 10. The power distributionmodule according to claim 8, wherein the bus interface comprises avoltage sensing comparator configured to receive and monitor voltage onthe power distribution bus.
 11. The power distribution module accordingto claim 8, additionally comprising memory storing a power systemdatabase identifying a power available for the at least one USB chargingport.
 12. The power distribution module according to claim 11, whereinthe power system database identifies a plurality of other powerdistribution modules connected to the power distribution bus and a totalpower required by each other power distribution module.
 13. The powerdistribution module according to claim 12, wherein the microcontrolleris configured to transmit a signal over the power distribution bus toupdate the power system database each time a device is connected to ordisconnected from the at least one USB charging port.
 14. A method fordistributing power from at least one power supply through a plurality ofpower distribution modules in communication over a power distributionbus, each power distribution module of the plurality of powerdistribution modules including at least one USB charging port, themethod comprising: maintaining, in memory at each power distributionmodule, a power system database identifying each power distributionmodule of the plurality of power distribution modules and a total powerrequired by each power distribution module of the plurality of powerdistribution modules; and controlling, by a microprocessor of each powerdistribution module, a supply of power from the at least one powersupply to devices connected to the at least one USB charging port of thepower distribution module based on the power system database.
 15. Themethod according to claim 14, additionally comprising: updating, at eachpower distribution module, the power system database each time a deviceis connected to or disconnected from the at least one USB charging portof any of the power distribution modules of the plurality of powerdistribution modules.
 16. The method according to claim 15, additionallycomprising: transmitting, by a power distribution module of theplurality of power distribution modules, a signal over the powerdistribution bus each time a device is connected to or disconnected fromthe at least one USB charging port of the power distribution module ofthe plurality of power distribution modules.
 17. The method according toclaim 16, additionally comprising: executing, by each power distributionmodule of the plurality of power distribution modules, an incrementalsearch protocol to identify the other power distribution module of theplurality of power distribution modules and the total power required byeach of the other power distribution modules.
 18. The method accordingto claim 14, additionally comprising: updating, at each powerdistribution module, the power system database each time a powerdistribution module of the plurality of power distribution modules ispowered on.
 19. The method according to claim 14, wherein each powerdistribution module of the plurality of power distribution modules isidentified in the power system database by a unique serial number. 20.The method according to claim 14, wherein the power system databaseadditionally stores a total power available from the at least one powersupply.